JAVA，报错，请问是哪里的问题？该如何解决？

JAVA，报错，请问是哪里的问题？该如何解决？

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class JavaDemo5 {
    public static void main(String[]args){
        list<Course> myList = new ArrayList<Course>();
        myList.add(new OptCourse("古典乐鉴赏",1,"良"));
        myList.add(new OptCourse("书法",1,"优"));
        myList.add(new OptCourse("交谊舞",2,"良"));
        for(int i = 0;i < myList.size();i++){
            Course c = myList.get(i);
            c.printInfo();
        }
        for (Course c:myList){
            c.printInfo();
        }
        Iterator<Course> iterator = myList.iterator();
        while (iterator.hasNext()){
            Course c = iterator.next();
            c.printInfo();
        }
    }
}

第七行：改为List myList = new ArrayList();

发个报错截图